Jamaica's Andrew Chin, better known as Brushy One String, was a crowd pleaser at last year's Jazz Fest, playing an acoustic guitar with a single string (see the photo above).
Brushy's act is an object lesson in doing more with less. He makes engaging music by combining his soulful vocals (alternating between blues, reggae, and rap singing styles) with rhythmic explorations of the precussive possibilities of his guitar's body. And, of course, that one string.
If you want to know more about Brushy, see Laura McNight's NOLA.com piece from last May.